Gwen Stefani battled through constant nausea to complete her 2005 solo tour while she was pregnant.

The No Doubt frontwoman was expecting her first son, Kingston, while working on her debut solo record Love. Angel. Music. Baby., and despite her delicate condition, she set out on her gruelling Harajuku Lovers Tour to promote the album.

The star insists the trek was "torture", because her pregnancy left her feeling sick throughout most of her performances.

She tells Vogue magazine, "I did my first solo record and went on tour while I was pregnant. I would want to throw up during certain songs. Certain outfits would make me sick. It was torture. I toured until I was four-and-a-half months pregnant, showing."

However, Stefani refused to stop working, and returned to the road after the birth - even though she was nursing a child.

She adds, "I came home and had Kingston, and when he was eight months old, I went back on the road. I nursed him for 14 months, so I would literally do my hair and make-up, go back to the bus, nurse him, put him down, and walk out onstage. And I did that for 100 shows."